JPS54162476A - Semiconductor device and its manufacture - Google Patents

Abstract

PURPOSE:To establish the power transistor high in the reliability and greater in the current amplification factor by coating the mesa surface of the transistor with continuous thermal oxidation film. CONSTITUTION:The N<->type layer 51 being the collector region and the P type layer 54 being the base region are grown with lamination on the N<+> type Si substrate 52, they are covered with the SiO2 film 55, the opening 56 is provided to diffuse the N<+> type emitter region 57 in the layer 54. Further, the film 55 is removed, the BSG film 58 is coated on the entire surface, the depth of the region 57 is made deeper with heat treatment to form the shallow P<+> type emitter region 64 in the layer 54 at the both sides. After that, the film 58 is removed, and on the regions 57 and 64, respectively the SiO2 film 68' and the Si3N4 film 78', for the contact forming mask are provided, they are covered with the resist film 88, and the concave is made on the region covering the regions 57 and 64 with etching. Further, the entire surface is protected with the resist 88', and after mesa etching for the both ends, the entire device is covered with the SiO2 film 98 in continuity itself with heat treatment under oxidized atomosphere. Then, the films 78' and 68' are removed attach the electrode 64.